Problem 3. [15 points] The following measurements were made at a potential site for a wind farm: The turbines have blade length of 20 m, overall efficiency is 0.3 (constant for all wind speed), the density of air is 1 kg/m3. a) A wind turbine has a cut-in speed at 3 m/s and a cut-out speed at 7 m/s. Find the average speed which the turbine operates at and the average power produced by the turbine.

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?

Apiping systems consists of 6 m of 6-std type k and 12 m of 4-std type k, both drawn copper tubing. the system conveys ethylene glycol at a rate of 0.013 m3/s. the pressure drop across the system is to be calculated. there are two 90° elbows in the 6-in pipe, a reduction from the 6-in pipe to the 4-in pipe and four 90° elbows in the 4-in pipe. all fittings are soldered (same as flanged) and regular. the inlet and outlet of the system are at the same height.